Ongoing research has been intensively conducted to analyze a user's gesture using a device such as a camera and to adopt the user's gesture as a user interface, thereby replacing or using together various user interface devices such as touch pads or touch screens as have been generally used.
However, when in analyzing a user's gesture and operating in response thereto, a plural of gesture's are made by plural users, it needs to be determined which user's gesture is to be analyzed and used as an input to an electronic device.
To address this, a concept for the gesture, “control authority”, has been created, and there has been intensive research as to methods of users' obtaining the control authority for gesture entry and/or methods of transferring the control authority from a user to another.